This invention relates generally to hearing aids and more particularly to an interconnect system for electronically coupling a conventional hearing aid to an audio signal such as that supplied by landline and cellular telephones, as well as by computers, stereo sound systems, tape cassette players, televisions, radios, compact disc players, laser disc players, telephone answering machines, telecopiers, electronic keyboards, aircraft communication systems, etc.
The more than 30 million hearing impaired persons in the U.S. alone are presently unable to use standard telephone instruments that are in common use by persons having normal hearing ability. A number of so-called TDD products (telecommunication devices for the deaf) are available in the marketplace. These products are typically nothing more than terminals that transmit typed messages over telephone lines to a compatible terminal or to relay operators at the receiving end of the line. These prior art TDD terminals are disadvantageous in that they do not meet the accessiblity needs of hearing impaired persons. Sound amplification products also exist in the prior art, but they simply do not amplify to the extent required to benefit a hearing disabled person. The 18-30 decibels of amplification typically realized from these prior art amplification products will not benefit a person suffering from even a moderate hearing loss, let alone one who is profoundly deaf.
Exemplary of the prior art related to the present invention are several U.S. patents located by applicants in the course of a preliminary novelty search. U.S. Pat. No. 3,862,378 to Norris is directed to an ear set with miniaturized electronic sound receiving and emitting equipment, in which the housing contains all or a portion of the electronic equipment and has pivotally connected thereto a spring loaded lever to be placed behind the ear, the free end of which is by the preloaded spring continuously urged toward the housing.
U.S. Pat. No. 4,137,431 to Pallesen is directed to a cable connector for the connectin of an electrical cable to or near the ear placed hearing aid, for instance, hearing spectacles or a hearing aid placed behind the ear. The connector comprises terminals secured to the cable, which terminals contact corresponding terminals in the housing during the conecting action. The cable connector further comprises a terminal holder secured to the cable, and the cable connector is arranged to engage around and come into snap engagement with the hearing aid. Pairs of corresponding terminals are mounted with one terminal in the cable connector secured to the cable in such a way as to be placed opposite each other by connecting operation and to press resiliently against each other.
U.S. Pat. No. 4,403,120 to Yoshimi is directed to a high performance and compact earphone which includes a speaker unit and a case in which the speaker unit is mounted. The earphone is firmly fitted in the ear cavity by the resilience and friction of the ear.
U.S. Pat. No. 4,420,657 to Larkin is directed to a lightweight adjustable headset for use with telephones including a housing having a microphone boom mounted in a manner to permit rotational and translational movement.
U.S. Pat. No. 4,539,439 to Strothmann et al. is directed to a connecting cord having a plug at each end, either of which can be plugged into a receptacle hearing aid while the other plug is plugged into an external microphone.
U.S. Pat. No. 4,701,958 to Neth is directed to an automatic gain control circuit for an output signal of a magnetic earpiece of a heaing aid, which comprises a voltage source, an output amplifier stage having an input connected to the voltage source and an output connected to the magnetic earpiece, the earpiece having a working winding connected between the amplifier stage output and the voltage source, and a control loop for automatic gain control.
U.S. Pat. No. 4,723,293 to Harless is directed to a hearing aid apparatus having a housing containing components such as a microphone, an amplifier, and an earphone. A terminal having contacts for connection to a signal line is applied to the housing.
U.S. Pat. 4,930,156 to Norris is directed to a telephone speaker/microphone device for suspending in a user's ear to enable hands-free communication without feedback. The device utilizes control circuitry which is capable of interconnecting microphone and speaker leads from a telephone or other communication device to a speaker element and microphone element which are embodied in a single earpiece and suspended at the user's ear. The speaker element and microphone element are positioned sufficiently close and are wired so that the speaker signal is approximately 180 degrees out of phase with the microphone signal and results in cancellation of feedback by virture of the out-of-phase relationship.
U.S. Pat. No. 5,058,155 to Larsen is directed to a multipurpose headset amplifier for connecting a headset to a telephone instrument. The device comprises a housing having an ascending, thready holder for a headset, the telephone instrument and for the telephone instrument's handset. The housing has, at the upper side thereof, a manual operating member for the adjustment of the device, and manual controls at the underside for the adaptation of a headset to the impedance and signal level of any telephone instrument.
U.S. Pat. No. 5,086,464 to Groppe is directed to an adjustable telephone headset for the hearing impaired comprising a left and a right ear piece, a speaker within each ear piece, an input device, such as a microphone or magnetic induction pickup within one of the ear pieces, and an amplifier connected between the input device and the speaker. Optionally, a switch may select between either a microphone receiver against the microphone or a magnetic induction pickup as the choice of input device. A wearer of the headset may place a telephone receiver against the microphone or magnetic induction pickup, allowing an amplified telephone conversation to be heard by both ears.
The prior art sound amplification systems typified by the foregoing references have simply not provided sufficient clarity, especially for those persons suffering severe hearing impairment.